The present invention relates to a moving pictures display apparatus system, and, more particularly, to a moving pictures display method and moving pictures display apparatus which are adapted to computer systems having an exclusive bus for moving pictures and a medium for storing codes for displaying moving pictures.
The entire contents of Japanese Patent Application No. 8-44806 filed on Mar. 1, 1996 are incorporated herein by reference.
Personal computers which can use PC cards that conform to the PCMCIA (Personal Computer Memory Card International Association) standards and JEIDA (Japanese Electronics Industry Development Association) standards are becoming popular these days. Recently, various developments have been made to use the PC cards as a video capture card for controlling the input and output of moving picture data, an MPEG (Moving Picture Coding Experts Group) decoder card and the like.
To efficiently process a vast amount of data like moving picture data, it becomes popular to design personal computers with system architectures which use the PCI local bus that can permit fast data transfer. Even the PCI local bus has a limit to the data transfer performance. When a PC card is used as a video capture card or an MPEG decoder card as mentioned above, therefore, the data transfer performance of the PCI local bus is insufficient.
In this respect, developments on techniques for using an exclusive bus for moving pictures, called "ZV (Zoomed Video) port," to directly connect a PC card to a display controller have recently started. The ZV port can permit a PC card to directly send video data and audio data to a display controller and an audio controller respectively without using the system bus. This overcomes the inconvenient long occupying of the system bus by the transfer of a vast amount of video data, and thus can allow moving pictures to be displayed without degrading the system performance. The ZV point is disclosed in a U.S. patent application Ser. No. 08/458,690 filed Jun. 2, 1995.
In conventional systems for transferring moving picture data to the display controller using such an exclusive moving picture bus, however, the displayable window size (the resolution of moving pictures) of moving picture data is determined specifically by software which controls the transfer of the moving picture data. The conventional systems cannot therefore display moving picture windows which are larger than the window size determined by the software.
There is another shortcoming originating from the system display performance such that when moving pictures whose resolution is greater than a certain level are displayed, the amount of transfer of moving pictures to a display monitor from a video memory per unit time becomes insufficient, thus causing a disturbance on the display screen.